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<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    <script>
        let a = 0
        let b = async () => {
            a = a + await 10
            console.log('2', a) // -> '2' 10
        }
        b()
        a++
        console.log('1', a) // -> '1' 1
    </script>
</body>

</html>